<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style type="text/css">
        .container {
            width: 100%;
            height: 500px;
            min-width: 500px;
            overflow: scroll;
        }
        .left, .right {
            border: 1px solid #ccc;
            font-size: 22px;
            color: #333;
            font-weight: bold;
            text-align: center;
            line-height: 500px;
            float: left;
        }
        .right {
            border-left: 0 none;
        }
    </style>
</head>
<body>
<div class="container">
    <div class="left">left<div class="drag"></div></div>
    <div class="right">right</div>
</div>
    <script>
        var offsetLeft,offsetTop,timer,mouse_x,mouse_y,margin_left,margin_top;
        var to_x,to_y;
        var leftDiv=document.getElementsByClassName("left")[0];
        var rightDiv=document.getElementsByClassName("right")[0];
        var drag=document.getElementsByClassName("drag")[0];
        rightDiv.onmouseover=function () {

        }
    </script>
</body>
</html>